Research On Control System Of Static Var Generator Based On DSP

With the continuous expansion of the scale of China's power system construction,the reactive power needed by all kinds of power equipment is increasing,which has a great impact on the power quality of the power system.In order to improve the power quality of the power grid,reactive power compensation is an important and effective measure,and it is also an important part in the construction of smart grid.Static var generator is a kind of advanced reactive power compensation device.Compared with the traditional reactive power compensation device,SVG can track and compensate reactive power quickly and accurately,suppress voltage fluctuation and flicker.Firstly,the background and significance of reactive power compensation are introduced.The development process of reactive power compensation device are introduced.The development trend of SVG in the future is analyzed.Then,the basic structure,working principle and working process of the static var generator are analyzed,and the mathematical model of the SVG in the dq coordinate system is established according to the instantaneous reactive power theory.Secondly,according to the characteristics of strong coupling,nonlinear of static var generator,a new type of double closed loop control strategy is proposed,in which the current loop is controlled by the feedforward decoupling control without inductance,the voltage loop using sliding mode variable structure control.The control strategy is simulated and verified in the MATLAB/simulink environment.Simulation results show that the new control strategy can quickly track and compensate reactive power.For the load of the mutation and the change of inductance parameter,the system shows good robustness,and can maintain the network side under the unit power factor condition very well.At the same time,the DC side capacitor voltage can be raised quickly and maintained near the reference voltage.The simulation results show that the control system with the new double closed loop control strategy can track the reactive power quickly and is not affected by the change of inductance parameters.For the load mutation show good robustness,the control system can better maintain the network running under unit power factor,and the DC capacitor voltage can be quickly increased and maintained at a nearby reference voltage.Thirdly,in order to realize the effective compensation of reactive power in power system,this paper takes DSP TMS320F2812 as the main chip.In this paper,the hardware circuit of each function module of the SVG control system is designed,including signal acquisition and conditioning circuit,zero crossing detection circuit,IGBT driver amplifier circuit and drive protection circuit.In addition,each function module of the control system is designed in the CCS environment,including system initialization module,data processing module,PWM trigger pulse generation module and LCD module.Finally,On the basis of the hardware circuit and software program,the control system is debugged jointly.The experimental results show that the function of the designed control system is proved to be feasible,and the control effect is better.